IBM Nanowires Add Photonics to Silicon

In practice, GaAs nanowires could be dynamically strained to tune their properties in real-time or could be permanently strained to fix their functionality once and for all.

"In principle both solutions could be realized but, in my opinion, the most interesting solution is an implementation where one can continuously tune the strain," said Signorello. "This solution would also allow to control and continuously tune the color of the light emitted and could have a big impact, especially considering wavelength-division-multiplexing -- the possibility of transmitting data on different color-channels within the same fiber."

In IBM's current demonstration, a range of tunability of 200 meV was achieved, but potentially that could be expanded further, as has demonstrated in a previous publication. IBM also previously solved the problem of how to use epitaxial growth to install III-V nanowires on silicon substrates, which it detailed in a recent publication.

"We demonstrated that III-V nanowires of GaAs and InAs can be integrated directly on silicon
[100] wafers, which are the current industry standard," said Signorello. By integrating both light emitters and detectors on the same silicon substrate, IBM hopes to reduce the complexity of future nanophotonic chips that communicate among themselves using light instead of electricity.

IBM has been working long and hard to define the next generation of semiconductors--such as carbon based nanotube- and graphene-transistors. Nanowires made from III-V materials like GaAs, InGaAs and InAs however, may turn out to be easier to integrate into the CMOS design flow than carbon-based materials. What do you think?